Method of making an electrical connection to an insulated wire



y 1950 s. M. WEISBERG 2,515,105

v METHOD OF MAKING AN ELECTRICAL CONNECTION TO AN INSULATED WIRE Filed Aug. 8, 1947 3 Sheets-Sheet 1 FIIIIII IIIIII.

SIDNEY M. WEISBERG Arm/Mb.

July 11, 1950 S. M. 'WEISBERG METHOD OF MAKING AN ELECTRICAL CONNECTION TO AN INSULATED WIRE Filed Aug. 8, 1947 5 Sheets-Sheet 2 SIDNEY M. Wslsseae INVENTOR.

July 11, 1950 M METHOD OF MAKING ELECTRIC CONNECTION TO AN ULATED W Filed Aug. 8, 1947 3 Sheets-Sheet 3 FIG-.- 15. FIG: 17.

SIDNEY M. W BERG INV NTOR.

A TTORNE Y.

z WEISBERG 2,515,105

Patented July METHOD OF MAKING AN ELECTRICAL CON NECTION TO AN INSULATED WIRE Sidney M. Weisberg, Newark, N. J., assignor to Allied Electric Products, Inc., Irvington, N. J., a, corporation of New Jersey Application August 8, 1947, Serial No. 767,575

1 Claim.

. The invention of this patent application relates to attachment plugs andaims to provide a blade construction which will eliminate the need for soldering of wires and, in some instances, the nee-d for stripping the wires of insulation. This invention is related to that disclosed in copending application of even date, Serial No. 767,576, now abandoned.

Particularly it is a purpose'of the invention to provide a structure enabling the wires to be both electrically and mechanically connected with the blades, quickly and easily and without special preliminary preparation of the wires or the blades. Special objects are to accomplish these and other desired results with no increase in expense and, actually, at lower cost.

In line with all such objects, it is a purpose of the invention to effect the securing of the wires to .the blades firmly and permanently, with a strain relief effect and without adding to the bulk or size of the blades or the complete plug.

, Other desirable objects and the novel features through which the purposes of the invention are attained are set forth or will appear in the course of the following specification.

The drawing accompanying and forming part of the specification illustrates certain present practical embodiments of the invention. Structure, however, may be further modified as regards V the immediate illustration, all within the true intent and broad scope of the invention as hereinafter defined and claimed.

Fig. 1 infthe drawing is a perspective view showing one of the attachment plug blades with the end portion of an insulated wire ready to be electrically and mechanically united therewith;

Fig. 2 is a broken sectional detail illustrating the operation of forming the blade with sharp, rigid, projecting teeth for penetrating the insulation; and biting into the strands of the wire;

Fig.3 is a broken sectional view showing a form of die for rolling the toothed end of-the blade about the insulated wire; y

Fig. 4 is an elevation of the blade showing the wire connected therewith, the wire being broken away;

Fig. 5 is a cross sectional view as on substantially the plane of line 5-5 of Fig. 4;

Fig. 6 is a broken perspective view of a modification;

Figs. 7 and Bare broken and part sectional views illustrating another modification, Fig. {8 being on a larger scale than the other views. v Fig. 9 is a broken front elevation to show how,

.pair of wires;

if desired, a bared end portion of the wire may be soldered to the metal strip;

Fig. 10 is a plan view showing how the principle of the invention may be applied to connecting a Fig. 11 is a sectional view as on substantially the plane of line I l,l l of Fig. 10;

Fig. 12 is a plan view showing a pair of the connectors in use for completing two difierent lines of wiring and how such connectors may be protected within a casing, the upper half of the casing being removed in this view;

Fig. 13 is an edge View showing the complete casing enclosing the connected wires;

Fig. 14 is a plan view showing a form of connector for two, three or four wires;

Fig. 15 is a cross sectional view as on substantially the plane of line I5--l5 of Fig. 14;

Fig. 16 is a perspective view of a modified form of attachment blade construction; and

Fig. 17 is a broken sectional view showing these blades mounted in a plug body.

' In Fig. 1 there is shown an attach blade of the spring action type from such blades as heretofore co having an angled step in at the lower or i ner end thereof, provided with a circular, jag row of sharp teeth II. p

This terminal blade is unusual also has a notch l2 in the side edge of above and partly in the angled step.

This notch [2 forms a hollow for reception of the insulation l3 of the wire l4.

, Fig. 2 illustrates one simple and effective way of forming the, upstanding row of teeth II on the angled end of the blade, that is, by means of a tapered punch l5 operating to pierce and to draw the metal of the blade into the opening it inadie l1.

A die such as illustratedtapers and tears the flange of drawn metal about the opening into an irregular set of sharp, tapered teeth or points such as shown. The annular form gives these teeth a certain rigidity, strength and stiffness, enabling them to readily cut through the various kinds of insulation ordinarily employed with attachment plugs. This includes the .plastic insulations as well as the ordinary rubber, cotton and other more familiar insulations used on attachment plug wires.

Fig. 1 shows how the wire, without removal of any'insulatiom'may be placed on the step In in back of the ring of teeth and with the latter servingv thus to retain the, wire, in place against the back wall I8 and shoulder IQ of the blade.

that it e same,

end portions of the blade and a punch 24 guided down through the base at and carrying the rolling or bending die portion 20.

Fig. 4 shows the angled end portidn [D of the blade completely rolled about the end as the wire, with the circular row of teeth at I] impressed into and forced through the insulation into the stranded body of the wire.

Fig. 5 brings this out even more clearly, showing how the circular series of teeth actuauy fully and firmly penetrate and bite into the strands of the wire.

When the toothed angled end of the blade is rolled'ever the nd't'j'fthe'wire'that portion immediately adjoinin'gtlie end is left free in the notch I; and therefore can be bent, as shown in Fig.4, into a position substantially in alignment with the edgeof the blade. Tl'i is'bending provides a 'strai reuer and 'it locates the'wire substantially withii'i ;'t he boundary, lines of the blad so that it willnot project andwill not form a bumpon the side of a rubber plug cap whu rora11'gefiera1 purposes the sharp spurs orteeth 'II provide ample contact area between the blade and wire, there may be instances Where it' is desirable to provide surface engagement'be- I tween the bare wire'ah'dthe surface of the blade.

Sucha 'cohdition is shown i'nFig' T, where the "end of the re is ba'ra and doubled back, as indicated atZ'I, to lie against the back wall pornonla, against which it 'W'i'llf be clamped when the to'othedend portion I0 6f the bladelis rolled over, as shown in a larger scale in'Fig. '8.

Blade's'iprovid'ed with the-toothed angled ends and'notehed orflanged edgescan be produced at low cost and they'carry fin and or themselves integrahwi'le rebe ivi and attaching l'neans.

While a simple form" ofidieYmecha'n'ism .su'ch as illustrated in"Fig.3 'maybeprefer red generally for closing the toothed portion of the bladeover the 'wl'repitf'is centemplated thatsuch a Closing die 'lhay" beihoorpdi'atd in a pliers; construction or the like. "structure, howeven'is such that'this closing and connectingof the bla de to 'the Wire 4 to attachment plug blades, it will be evident from the foregoing that the invention may be employed with advantage in electrical connectors generally.

Such a connector is represented at 29, Figs. 10 and 11, in the form of a strip having bendable end lugs I Ila at the opposite ends, with ,a circular-series of spurs, teeth or prongs Ila to bite into and through the insulation of the wires 43a which are to be connected.

Fig. 10 shows the clearance notches I2a disposed diagonally opposite in the opposite ends of the strip so as to more or less balance the pull of the connected wires on the strip.

--Figs. Hand 13 show how after being connected bythe strip'connectors 29, they, the wire ends and connectors may be enclosed within a twopare-case's!) of insulating or other material, with the;parts suitably secured together as by means of an encircling ring, band or wire 3 I.

Figs. .14; and .15 show how the invention may be carried out in a 'c'onnectorforl any number of wires. In this particular'instance thesheet metal connector strip-32 is of generally rectangular shape and "with the barbed, bendable lugs or-tong'ues 'I'Ilaat alljfour' corners ;of thesaine so "that it maybe used 'for'connecting one wire such as 13a to one,"two 'or'three other gwi-res such as I31), I30, I301.

The connectors last described, like the "attachment blade form ofJc nnectQrsJmay .be used with'or without soldering the wires, as circumstances .inay dictate. IFigs. '16'and1l'7 show how; when the-invention is embodied in 'a jplug blade, :the wire clamping loop at the'i'n'ner end. ofthe blade may be extended and curved reverselyto form an outwardly projecting hook 33 for interlocking engageinent behind the shoulder provided in" the plug body 35 'at'theinne'r end'oiithe'blade receiving'pa'ssag'etfi.

Theplugfbody fshownisjjof rubber or plasticsoft enough to permit the blades b'eingpulled into place. I Y

The engagement ofjthejout-pturned hook ends 33 behindthe shou1ders'j34jlimits the movement of ,pulling'Tthe blades into -fiillyjseated position in the plug body .and .prevents .t em from afterward being pulled. out ,orbeconiin dose 'in the- "plug body. ."This constructioniena es thecompleted Dlugsto withstand'ithe 'usuai 'p'ullftests jand th'e like to which suchplugs, are sub ected. [jhe out- Ward projections ,33, atjthe ends {of the Wi e encircling 10'c' ps ,I]oy,.pressure againstjtheenclosing walls 3I.-.o't.the.wire,cavityjin.thaplugbody, causes the lodps to be held .cms aani the, ,more firmly may be accomplished'w'ith an "ordinary pair of pliers, 'or even with a hammeror other simple form of tool.

. The invention, whiledargely liniinatin'gfthe need'for soldering does not prevent soldering "of the wire I to the blade for connector 'stripif such is'j desired. In Fig. '7 the bardfehd jportio'nTTl of th'e wireinay be"s 'olde'red in the seat I8, I9, before th'esecuring portion 'IIJ .is'bent over "the same.

As an alternative, the bared "end 'po'rtionQZ I of the 'wire' may bebrollg'htout' and' th'eh-sbldr'ed over the-Outsideof thestrio as indi'oated'ati'28 in Fig. 9.

While particularlyuseful for'securing thewire's'.

" versely bending the end portion of a, shoe over the .wires with ithei sharp spurs "I I. onthe'se loops biting the .moreffirinly intoj'thawires.

"In gthe construc'tijo'n shownjin Figs; l 6 andjl'l the 'blades'; may'f'befah falike; ,so thatfwhen revers'e'd, as .they 'are'fin the seated frelation in -}-the plug, Fig? 17; 4 the two-iwi res=will-come out at the opposite sides df the' blades to substantially'ibal ance the pull on the plug. I

*Wvnatis=claimed is: Y r

The herein disclosed method-Ixfielectricahy con necting the conducting core and mechanicallydnterlock'ing both thercondu'c ting-eoreand: thegsurrounding insulationirofjaminsulated;,wire;w;ith an electrical 3connectorjandewhich, cornprises transstr;ip:-into a.-transversely'-,extending open w;

ceiving groove andthe end ,of ghe strip rejecting substantially at a right v angle from ,said .g TQQVe erg nd iew -sa l ee er x e- 5 ing end of the strip toward the side of the strip in which the groove is formed into an annular series of irregular, sharply pointed, tapered, sharp edged spurs projecting from the face of the strip, locating an insulated wire in said groove and in position between the formation of said groove and said projecting spurs and then bending the angularly extending end of the strip carrying said projecting spurs inwardly of the strip over said wire and driving said spurs through the insulation of the wire and into the conducting core of the wire.

SIDNEY M. WEISBERG.

REFERENCES CITED UNITED STATES PATENTS Number Number Name Date Ball Sept. 29, 1908 Thompson Mar. 19, 1929 Whisler June 10, 1930 Gilbert Apr. 24, 1934 Arey June 11, 1935 Popp Aug. 15, 1939 Laystrom Oct. 10, 1939 Chirelstein Aug. 4, 1942 Grohsgal Jan. 26, 1943 Chirelstein Nov. 2, 1943 McLarn Dec. 30, 1947 FOREIGN PATENTS Country Date Great Britain 1894 

